JP2015155645A - Steel pipe pile type pier and steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a steel pipe pile pier which can satisfy the required performance of a level-2 earthquake without increasing a plate thickness and enlarging a diameter.

SOLUTION: This steel pipe pile pier is constituted of a steel pipe pile row formed of a plurality of steel pipe piles 1 which are rooted into the sea bottom ground, and an upper construction 3 which is constructed in a region protruding above the sea level in the steel pipe pile row. The steel pipe pile 1 satisfies a relationship of φp≥4.39×10^-3/D between a diameter D of the steel pipe pile 1 and a curvature φp with respect to the whole elasticity moment of the steel pipe pile 1.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a steel pipe pile pier constructed in a harbor or a river, and a steel pipe pile used for a steel pipe pile pier.

Steel pipe pile piers built in harbors and rivers are referred to as “Technical Standards for Port Facilities / Comments (Edited by Japan Port Association) (Non-Patent Document 1)” (hereinafter referred to as “Port Standards”). ) Is a type of mooring facility designed in line with this, and in this specification, the horizontal jetty (see Fig. 14), where the back of the jetty is land, is arranged vertically from the land to the sea. A vertical pier (see FIG. 15), a dolphin for mooring a ship (see FIG. 16), and a detached pier (see FIG. 17) are referred to as a steel pipe pile type pier.
In FIG. 14, 1 is a steel pipe pile, 3 is a superstructure, 5 is a transfer plate, 7 is an L-shaped block, 9 is a covering stone, 11 is a sea level, and 13 is a sea bottom. 15 to 17, the same parts as those in FIG. 14 are denoted by the same reference numerals. In FIG. 17, 15 is a yard bridge, 17 is a sea side rail, 19 is a land side rail, and 21 is a caisson.

Steel pipe pile type pier is steel pipe pile (JIS A 5525) manufactured at the factory (hereinafter “steel pipe pile” is referred to as “steel pipe pile”) SKK400 (of steel yield strength described in port standards) Characteristic value is 235N / mm ² ), SKK490 (characteristic value of steel yield strength described in port standards is 315N / mm ² ), and multiple piles of steel pipe piles are reinforced concrete. It is constructed by integrating with a superstructure made of steel.
In this specification, the steel pipe pile is examined using the size described in “JIS A 5525” and the Young's modulus of the steel material is 2.06 × 10 ⁸ kPa.

"Technical standards for port facilities / comments (Japan Port Association)"

  The design method of steel pipe pile type jetty is designed for ship berthing force, seismic force, and load of cargo handling equipment that may be installed on the superstructure. Among them, in many cases, the cross section (steel pipe pile diameter, plate thickness, arrangement, etc.) of the steel pipe pile type jetty is determined by seismic force. According to the port standards revised in 2007, the seismic force is designed for Level 1 ground motion, which is likely to occur during the in-service period of the facility, and the largest expected Level 2 ground motion. . In particular, in an “earthquake strengthening facility” where earthquake resistance is required during an earthquake, it is essential to check for level 2 ground motions, and it is common to study by seismic response analysis using the finite element method.

  As a concrete design procedure, first, the cross-sectional force generated in the steel pipe pile with a steel pipe pile type pier as a frame structure against the fluctuation state (force due to ship berthing / towing, level 1 earthquake motion, etc.) Determine the cross-section so that it is less than the yield strength. Next, the verification for the accidental state (Level 2 ground motion) is examined by seismic response analysis.

The performance regulations for Level 2 earthquake of the seismic strengthening facility are as follows.
In the seismic strengthening facility (specific (emergency goods transportation support)), regarding the deformation of the quay normal (see Fig. 14), the limit value of the residual deformation is typically about 30 to 100 cm. Regarding the total plasticity of piles, “Verify that there are no piles that reach full plasticity at two or more places in the piles that constitute the pier. Is a pile whose bending moment has reached the total plastic moment. "
In this specification, the curvature φp (unit: 1 / m) corresponding to the total plastic moment is used as an index for checking the total plasticity of the pile. The curvature φp can be calculated by dividing the total plastic moment Mp by the bending stiffness EI (E is the Young's modulus of the steel material of the pile, and I is the secondary moment of inertia of the pile).

  Level 2 ground motions stipulated by port standards tend to become larger due to recent improvements in seismic observation networks and improvements in earthquake motion prediction technology. At points with large Level 2 ground motions, the required performance for deformation of quay normals Although satisfied, it seems that the total plasticity of the pile is not satisfied, and there are increasing opportunities to review the design cross section. To cope with this, for example, the thickness of the steel pipe pile is increased, and the diameter of the steel pipe pile is increased.

  Increasing the thickness of the steel pipe pile increases the bending stiffness of the steel pipe pile, but the curvature corresponding to the total plastic moment, which is an index related to the total plasticity of the pile, hardly changes. As the bending stiffness of steel pipe piles increases, the amount of residual deformation of the pier decreases, and in some cases, the generated curvature of the steel pipe piles can be reduced below the curvature φp corresponding to the total plastic moment. However, there is a problem that the steel weight of the steel pipe pile increases due to the accidental state with a very low probability of occurrence than the cross section determined in the variable state, leading to an increase in construction cost.

In addition, increasing the diameter of the steel pipe pile can increase the bending rigidity more efficiently than increasing the plate thickness, but on the other hand, increasing the diameter of the steel pipe pile is an index related to the total plasticity of the pile. The curvature corresponding to the total plastic moment becomes small. That is, the deformation performance is reduced. Therefore, it is difficult to satisfy the required performance of the entire plasticity of the pile unless the amount of residual deformation is very small. In addition, even if the required performance is satisfied, the steel pipe pile weight increases due to the accidental state with a much lower probability of occurrence than the cross section determined by the fluctuation state, as in the case of increasing the plate thickness. I have a problem that leads to cost increase.
Furthermore, the seismic response analysis used in the verification for Level 2 ground motion requires a great deal of time to create and analyze the analysis model, which is an issue for improving the efficiency of the design work.

As explained in the previous section, the amount of residual deformation of the steel pipe pile pier satisfies the required performance, but does not satisfy the required performance with respect to the total plasticity of the pile. Is none other than lacking.
As described above, the method of satisfying the required performance related to the total plasticity of the pile is to increase the rigidity of the steel pipe pile by increasing the plate thickness of the steel pipe pile or by increasing the diameter of the steel pipe pile. Although methods for satisfying the required performance by reducing the amount can be considered, the weight of the steel used increases in any case, leading to an increase in construction cost.
Then, the inventor considered raising the local deformation capacity of a pile in order to solve such a subject.
As an index of the deformability of the steel pipe pile, the curvature φp corresponding to the total plastic moment Mp can be used. φp = Mp / EI = 2εp / D (εp: maximum strain at the outer edge of the steel pipe pile when the pile reaches a fully plastic state, D is the diameter of the steel pipe pile) εp of the steel pipe pile of SKK490 If the Young's modulus is 2.06 × 10 ⁸ kPa, the value used in the design is about 0.197% to 0.199%, although it depends on the plate thickness. Therefore, the relationship is φp = (3.94 to 3.98) × 10 ⁻³ / D = α / D (α is a constant). From this equation, it is possible to increase the local deformation performance of the steel pipe pile by increasing α or reducing the diameter D of the steel pipe pile. It is difficult to reduce the diameter D unless there is a margin in the supporting capacity of the steel pipe pile and the residual deformation amount of the pier. Therefore, from the viewpoint of improving the deformation performance as compared with the prior art, as a guide for α, it is decided to increase it by 10% or more in order to clearly obtain the effect.
The present invention is based on the above findings, and specifically comprises the following configuration.

(1) A steel pipe pile pier according to the present invention includes a steel pipe pile row composed of a plurality of steel pipe piles embedded in the seabed ground, and a superstructure constructed at a portion protruding on the sea surface in the steel pipe pile row. In the steel pipe pile type pier, the steel pipe pile satisfies the relationship that the diameter D of the steel pipe pile and the curvature φp corresponding to the total plastic moment of the steel pipe pile are φp ≧ 4.39 × 10 ⁻³ / D It is characterized by this.

(2) Further, the steel pipe pile pier according to the present invention is characterized in that in the above described (1), φp ≧ 4.90 × 10 ⁻³ / D is satisfied.

(3) Moreover, the steel pipe pile pier according to the present invention is characterized in that in the above described (1), φp ≧ 5.65 × 10 ⁻³ / D is satisfied.

(4) Moreover, the steel pipe pile pier which concerns on this invention uses the steel pipe pile as described in said (1)-(3) for the part with the large curvature which arises in a steel pipe pile with respect to external force, and other parts are used for it. A steel pipe pile having a deformation performance lower than that of the steel pipe pile is used.

(5) Moreover, the steel pipe pile which concerns on this invention is a steel pipe pile in any one of said (1)-(4), Comprising: This steel pipe pile is formed with the spiral steel pipe, It is characterized by the above-mentioned. It is.

(6) Moreover, the steel pipe pile which concerns on this invention is a steel pipe pile in any one of said (1)-(4), Comprising: This steel pipe pile is formed with the ERW steel pipe, It is characterized by the above-mentioned. Is.

Since the steel pipe pile pier according to the present invention uses a steel pipe pile having a higher deformation performance than before, if it is a steel pipe pile type pier using a conventional steel pipe pile having a lower deformation performance, Although the required performance for the residual horizontal displacement is satisfied, even if the steel pipe pile exceeds the curvature corresponding to the total plastic moment in the underground, the plate thickness is increased or the diameter is increased. It is possible to satisfy the required performance without any problems.
Moreover, in the steel pipe pile type pier using the conventional steel pipe pile with low deformation performance, when the required performance for level 2 earthquake is satisfied, by using the steel pipe pile with high deformation performance according to the present invention, Compared to conventional materials, the pile diameter of steel pipe piles can be reduced and the plate thickness can be reduced. Thereby, it becomes possible to reduce the construction cost of a steel pipe pile type jetty.
As a method for manufacturing a steel pipe pile, a spiral steel pipe or an electric resistance steel pipe is preferable from the viewpoint of manufacturing cost and delivery date.

It is sectional drawing of the steel pipe pile type pier (initial section) regarding Embodiment 1. FIG. It is a figure which shows the earthquake response analysis result with respect to an initial section. It is a figure which shows a seismic response analysis result when plate | board thickness is 16 mm with respect to an initial section. It is a figure which shows a seismic response analysis result when plate | board thickness is 19 mm with respect to an initial section. It is a figure which shows a seismic response analysis result when a diameter is 1000 mm with respect to an initial section. It is a figure which shows a seismic response analysis result when a diameter is 1100mm with respect to an initial section. It is a figure which shows the seismic response analysis result at the time of setting it as the steel pipe pile which satisfy | fills (phi) p = 4.39 * 10 < ^-3 > / D with respect to an initial section (example of this invention). It is a figure which shows the earthquake response analysis result (when a level 2 earthquake is strong) with respect to an initial section. It is a figure which shows an earthquake response analysis result (when a level 2 earthquake is strong) when plate | board thickness is 19 mm with respect to an initial section. It is a figure which shows an earthquake response analysis result (when a level 2 earthquake is strong) when a diameter is 1100mm with respect to an initial section. It is a figure which shows the seismic response analysis result (when a level 2 earthquake is strong) at the time of setting it as the steel pipe pile which satisfy | fills φp> = 4.90 * 10 < ^-3 > / D with respect to an initial section (example of this invention). It is a figure which shows the seismic response analysis result (when a level 2 earthquake is strong) at the time of setting it as the steel pipe pile which satisfy | fills (phi) p = 5.65 * 10 < ^-3 > / D with respect to an initial section (example of this invention). It is a figure which shows the seismic response analysis result (when a level 2 earthquake is strong) at the time of using a steel pipe pile with a high deformation | transformation performance in the part with a large generation | occurrence | production curvature (example of this invention). It is an example of sectional drawing and a top view of a horizontal jetty. It is an example of sectional drawing and a top view of a longitudinal jetty. It is an example of sectional drawing and a top view of a dolphin. It is an example of sectional drawing and a top view of a detached peer.

[Embodiment 1]
The embodiment will be described by taking a steel pipe pile pier having a depth of -11 m as shown in FIG. In FIG. 1, the same parts as those in FIG. 14 are denoted by the same reference numerals.
The required performance for level 2 earthquakes in this case is as follows: (1) Curvature of steel pipe piles corresponding to the total plastic moment in the ground with reference to the seismic strengthening facility (specified (for emergency goods transportation)) described in the port standards (2) The residual horizontal displacement of the steel pipe pile pier after the earthquake was about 30-100 cm.
(1) is a paraphrase of the part corresponding to the port standard "There is no pile that has reached full plasticity in two or more places." When total plasticity is reached at two locations on the pile, it is common to reach full plasticity at one boundary between the pile and superstructure and at one or more locations in the ground. Since the boundary between the pile and the superstructure is on the sea surface, it can be easily repaired even if it is completely plasticized. On the other hand, if it becomes fully plastic in the underground, it is difficult to repair and it is not easy to discover that it is fully plastic. Therefore, “there is no pile that reaches full plasticity at two or more locations” can be rephrased as “does not exceed the curvature corresponding to the total plasticity in the ground”.

Steel pipe pile type jetty determined for variable load conditions (steel pipe pile is SKK490 material with a diameter of 900mm and a plate thickness of 14mm. This section is defined as the "initial section". Corresponds to the total plastic moment. The curvature φp is 4.39 × 10 ⁻³ (φp = 3.95 × 10 ⁻³ /D=3.95×10 ⁻³ /0.9=4.39×10 ⁻³ ), but it is an earthquake for an accidental level 2 earthquake Response analysis was performed.
Table 1 shows the main ground constants used in the analysis.

The result of the earthquake response analysis is shown in FIG. In the figure, the deformation figure of the steel pipe pile type jetty, the value of the residual horizontal displacement, and the point where the curvature exceeding the curvature φp corresponding to the total plastic moment occurred in the steel pipe pile are indicated by ○. As shown in Fig. 2, the residual horizontal displacement is 95cm, which satisfies the required performance, but the curvature corresponding to the total plastic moment exceeds about 1.4 times in the underground part of the steel pipe pile on the land side. (Φ = 6.11 × 10 ⁻³ ). In other words, the steel pipe pile pier as a whole satisfied the residual horizontal displacement after the level 2 earthquake, but the deformation performance of the steel pipe pile itself was insufficient locally in the ground.

For such a result, we first considered increasing the thickness of the steel pipe pile.
If the plate thickness is increased, the bending rigidity of the steel pipe pile will increase and the residual horizontal displacement of the steel pipe pile jetty can be reduced. Therefore, the curvature generated in the steel pipe pile ground should be smaller than the curvature corresponding to the total plastic moment. Aimed at.

When the plate thickness is 16 mm, the bending rigidity EI is 1.16 times, the steel weight is 1.14 times, and the curvature φp with respect to the total plastic moment is 1.00 times. The earthquake response analysis result in this case is shown in FIG.
At the plate thickness of 16 mm, the residual horizontal displacement was suppressed to 90 cm (0.95 times the initial cross section), but the curvature corresponding to the total plastic moment exceeded the ground part of the steel pipe pile on the land side.

If the plate thickness is further increased to 19 mm, the bending rigidity EI is 1.33 times, the steel weight is 1.35 times, and the curvature φp for the total plastic moment is 1.01 times. FIG. 4 shows the seismic response analysis result in this case. At the plate thickness of 19mm, the residual horizontal displacement was suppressed to 85cm (0.90 times the initial cross section), and the curvature of the steel pipe pile on the land side was less than the curvature corresponding to the total plastic moment, satisfying the required performance.
From these results, even if the plate thickness is increased, the curvature with respect to the total plastic moment is almost the same, but the bending rigidity increases. Therefore, if the residual horizontal displacement can be suppressed with the increased bending rigidity, the curvature generated in the steel pipe pile can be reduced. It became clear that it can be below the curvature corresponding to the total plastic moment.

Next, it was examined to increase the diameter of the steel pipe.
Increasing the diameter of the steel pipe can effectively increase the bending stiffness of the steel pipe pile, but there is a trade-off relationship that the curvature with respect to the total plastic moment is reduced, so how to balance the two? is important.
If the diameter of the steel pipe pile is 1000 mm, the bending stiffness EI is 1.38 times, the steel weight is 1.11 times, and the curvature φp for the total plastic moment is 0.90 times. Although bending rigidity can be increased with less steel weight than increasing the plate thickness, the curvature with respect to the total plastic moment has become smaller. The earthquake response analysis result in this case is shown in FIG. Residual horizontal displacement is suppressed to 87cm (0.92 times the initial cross section), but curvature exceeding the total plastic moment occurs in the underground.

  If the diameter of the steel pipe pile is further increased to 1100 mm, the bending stiffness EI is 1.84 times, the steel weight is 1.23 times, and the curvature φp for the total plastic moment is 0.82 times. FIG. 6 shows the seismic response analysis result in this case. Residual horizontal displacement was suppressed to 81 cm (0.85 times the initial cross section), and the steel pipe pile on the land side had a curvature below the total plastic moment, satisfying the required performance.

  From the above examination results, it is possible to satisfy the required performance that the steel pipe pile does not exceed the curvature corresponding to the total plastic moment in the ground by increasing the plate thickness or increasing the diameter of the steel pipe pile. However, it is a disadvantage that 1.33 times the steel weight is required to increase the plate thickness, 1.23 times the steel weight is required to increase the diameter, and the construction cost of the steel pipe pile increases. It became clear that this occurred.

Therefore, in the present embodiment, it has been considered to improve the deformation performance of the steel pipe pile. Specifically, the steel pipe of 4.88 × 10 ⁻³ whose curvature φp corresponding to the total plastic moment is about 10% higher than 4.39 × 10 ⁻³ was used.
The formula for calculating the curvature is φp = 4.39 × 10 ⁻³ /D=0.39×10 ⁻³ /0.9=0.88×10 ⁻³ . In order to exert its deformation performance is made possible by using a steel pipe pile that the characteristic values of the steel yield strength can ensure about 10% higher 350 N / mm ² than 315N / mm ^2. It should be noted that there is no change in bending rigidity and steel weight only by improving the deformation performance.

FIG. 7 shows the seismic response analysis result using the steel pipe pile with excellent deformation performance. Residual horizontal displacement is 91 cm (0.97 times the initial cross section), and the suppression effect is small, but no curvature exceeding the total plastic moment has occurred in the underground part, and “the curvature corresponding to the total plastic moment in the steel pipe pile is in the underground part. Satisfies the required performance. Thus, in the embodiment, the required performance could be satisfied by using a steel pipe pile with high deformation performance that satisfies φp ≧ 4.39 × 10 ⁻³ / D for the steel pipe pile type jetty.

  In this embodiment, an example was shown in which the steel pile pile jetty determined for the load conditions in the variable state did not satisfy the required performance for level 2 earthquake motion. However, even if the required performance is satisfied, the diameter and thickness of the steel pipe pile can be reduced by using the steel pipe pile having higher deformation performance than SKK490. As a result, it is possible to reduce the construction cost of the steel pipe pile type jetty.

[Embodiment 2]
In the same steel pipe pile type jetty examined in Embodiment 1, the case where a level 2 earthquake became large was examined. Specifically, the maximum acceleration of Level 2 ground motion used in Embodiment 1 was increased by 7.5%. The required performance is the same as in the first embodiment. FIG. 8 shows the result of the earthquake response analysis performed on the initial cross section shown in FIG. The residual horizontal displacement is 109cm, which satisfies the required performance in general, but exceeds the curvature corresponding to the total plastic moment at the land side by about 1.9 times (φ = 8.56 × 10 ^-3 ) . In other words, the steel pipe pile pier as a whole was generally satisfied with the residual horizontal displacement after the level 2 earthquake, but the deformation performance of the steel pipe pile itself was insufficient locally in the ground.

Here, as in the first embodiment, the plate thickness was first increased to 19 mm. The earthquake response analysis result in this case is shown in FIG. Residual horizontal displacement is suppressed to 98cm (0.90 times the initial cross section), but curvature exceeding the total plastic moment has occurred in the underground.
Next, the diameter of the steel pipe pile was increased to 1100 mm. The earthquake response analysis result in this case is shown in FIG. Residual horizontal displacement is suppressed to 92cm (0.84 times the initial cross section), but curvature exceeding the total plastic moment has occurred in the underground.

Therefore, earthquake response analysis with gradually increasing deformation performance was performed. As a result, when the curvature φp corresponding to the total plastic moment is 5.44 × 10 ⁻³ (φp = 4.90 × 10 ⁻³ /D=4.90×10 ⁻³ /0.9=5.44×10 ⁻³ ), Curvature exceeding the plastic moment no longer occurs. The earthquake response analysis result in this case is shown in FIG.
By using a steel pipe pile with high deformation performance that satisfies φp ≧ 4.90 × 10 ^-3 / D for the steel pipe pile type jetty, the residual horizontal displacement is suppressed to 102 cm (0.94 times the initial section). The required horizontal displacement after the earthquake of about 30 to 100 cm was almost satisfied.

Furthermore, the seismic response analysis results when the curvature φp corresponding to the total plastic moment is 6.28 × 10 ⁻³ (φp = 5.65 × 10 ⁻³ /D=5.65×10 ⁻³ /0.9=6.28×10 ⁻³ ) As shown in FIG. By using a steel pipe pile with high deformation performance that satisfies φp ≧ 5.65 × 10 ⁻³ / D for the steel pipe pile jetty, the residual horizontal displacement is suppressed to 98 cm (0.04 times the initial cross section). The required performance of "the residual horizontal displacement after the earthquake of about 30-100 cm" was fully satisfied.

[Embodiment 3]
In the first embodiment and the second embodiment, the steel pipe piles constituting the steel pipe pile type pier have been studied on the premise that they have the same diameter, plate thickness, and deformation performance.
On the other hand, Embodiment 3 demonstrates the example using the steel pipe pile which is excellent in a deformation | transformation performance only in the part where a curvature becomes large.
In the initial cross section of the second embodiment, a curvature exceeding the total plastic moment is generated in the underground portion of the steel pipe pile on the land side (see FIG. 8). For this cross section, we examined the use of steel pipe piles with excellent deformation performance in the part where the generated curvature is large in the underground. Specifically, a steel pipe pile with a curvature of 6.28 × 10 ^-3 for the total plastic moment of 8.3m from -15m to -23.3m (highly deformable steel pipe pile satisfying φp ≧ 5.65 × 10 ^-3 / D) Applied. The earthquake response analysis result in this case is shown in FIG. The residual horizontal displacement is 109cm, which is the same as the initial section, but no curvature exceeding the total plastic moment has occurred in the underground. Thereby, the required performance that "the steel pipe pile does not exceed the curvature corresponding to the total plastic moment in the underground" can be satisfied.
In this example, the steel pipe piles with the same deformation performance are applied to all the steel pipe piles at -15m to -23.3m. However, from the analysis results, the steel pipe piles at the sea side and the center have a little more deformation performance. Inferior ones can be used. That is, it is possible to construct an economical steel pipe pile type pier by using a steel pipe pile having an optimal deformation performance according to the curvature generated in the steel pipe pile.

DESCRIPTION OF SYMBOLS 1 Steel pipe pile 3 Superstructure 5 Delivery plate 7 L-shaped block 9 Cover stone 11 Sea surface 13 Sea bottom 15 Yard bridge 17 Sea side rail 19 Land side rail 21 Caisson

(1) A steel pipe pile pier according to the present invention includes a steel pipe pile row composed of a plurality of steel pipe piles embedded in the seabed ground, and a superstructure constructed at a portion protruding on the sea surface in the steel pipe pile row. In steel pipe pile pier composed of
The steel pipe pile shall be excellent in deformation performance in which the curvature φp corresponding to the total plastic moment only satisfies the part where the generated curvature is large in the underground part of the steel pipe pile satisfies φp ≧ 5.65 × 10 ⁻³ / D. Is characterized in that its deformation performance is lower than that of the aforementioned part .

( 2 ) Moreover, the steel pipe pile which concerns on this invention is a steel pipe pile as described in said (1 ) , Comprising: This steel pipe pile is formed by the spiral steel pipe, It is characterized by the above-mentioned.

( 3 ) Moreover, the steel pipe pile which concerns on this invention is a steel pipe pile as described in said (1 ) , Comprising: This steel pipe pile is formed by the ERW steel pipe, It is characterized by the above-mentioned.

The steel pipe pile pier according to the present invention is excellent in deformation performance in which the curvature φp corresponding to the total plastic moment only in the portion where the generated curvature is large in the underground part of the steel pipe pile satisfies φp ≧ 5.65 × 10 ⁻³ / D, Since the other parts have lower deformation performance than the above parts , if the steel pipe pile type pier using a conventional steel pipe pile with lower deformation performance, the required performance for residual horizontal displacement in relation to the required performance for level 2 earthquake However, even if the steel pipe pile exceeds the curvature corresponding to the total plastic moment in the underground, it satisfies the required performance without increasing the plate thickness or increasing the diameter. It becomes possible to make it.
Further, in steel pipe pile type pier using a conventional steel pipe pile low strain capacity, if such meets the required performance for the level 2 earthquake, by using steel Kankui of the present invention, a conventional material In comparison, it is possible to reduce the pile diameter of the steel pipe pile or reduce the plate thickness. Thereby, it becomes possible to reduce the construction cost of a steel pipe pile type jetty.
As a method for manufacturing a steel pipe pile, a spiral steel pipe or an electric resistance steel pipe is preferable from the viewpoint of manufacturing cost and delivery date.

Claims (6)

In a steel pipe pile pier composed of a steel pipe pile row composed of a plurality of steel pipe piles embedded in the seabed ground, and a superstructure constructed in a portion protruding on the sea surface in the steel pipe pile row,
In the steel pipe pile, the diameter D of the steel pipe pile and the curvature φp corresponding to the total plastic moment of the steel pipe pile satisfy the relationship of φp ≧ 4.39 × 10 ⁻³ / D. The steel pipe pile type jetty according to claim 1, wherein φp ≧ 4.90 × 10 ⁻³ / D is satisfied. The steel pipe pile type jetty according to claim 1, wherein φp ≧ 5.65 × 10 ⁻³ / D is satisfied.   The steel pipe pile according to any one of claims 1 to 3 is used for a portion having a large curvature generated in the steel pipe pile with respect to an external force, and a steel pipe pile having a lower deformation performance than the steel pipe pile is used for the other portions. Steel pipe pile type pier.   It is a steel pipe pile in any one of Claims 1-4, Comprising: This steel pipe pile is formed of the spiral steel pipe, The steel pipe pile characterized by the above-mentioned.   It is a steel pipe pile in any one of Claims 1-4, Comprising: This steel pipe pile is formed of the ERW steel pipe, The steel pipe pile characterized by the above-mentioned.

Images